PKN
Committees X, Y and Z have at least three members each. No two of these committees, have any common members. The average (arithmetic mean) ages of the members of X, Y and Z are 30 years, 35 years and 40 years respectively. The average age of the members of X, Y and Z together is 35 years. Does X have more members than Y?
(1) The average age of the members of Y and Z together is at least 38 years
(2) The average age of the members of X and Y together is at most 33 years.
Source:- Time4education
let the number of members in Committees X, Y & Z be \(x, y\) & \(z\) respectively. need to find whether \(x>y\)
given \(30x+35y+40z=35(x+y+z) =>30x+35y+40z=35x+35y+35z\)
\(=>x=z\)
Statement 1: implies \(35y+40x ≥ 38(y+z)=>2z≥3y\)
\(=>x≥\frac{3}{2}y\). Hence \(x>y\).
SufficientStatement 2: implies \(30x+35y≤33(x+y)\)
\(=>2y≤3x => x≥\frac{2}{3}y\). So \(x>y\) or \(x<y\).
InsufficientOption
ALoved your approach ! I analyzed it instead and took me three minutes.
Can you please explain to me how in statement 1 you were sure that x>y while in statement 2 x<y or x>y
I have missed a lot of questions because of this.
This is what i havae always applied (is probably wrong) , in an equality x=5y . x>y since y needs to be multiplied by a larger number to balance out the x.
For inequalities this does not work at all. This was quite evident with this one. Please guide !!!